polini ignition timing need help

[manny]

Ok so I installed the polini inner rotor ignition the instructions for the timing said to set it at 4.5mm from udc (upper dead center)for a 70cc
I tried to check the advance with a timing light but I have to get a tach .
I just found the instructions from the evo A/C cylinder I,'m using and it says
set the ignition advance:
(1) at 13 before tdc at 7000rpm
(2) at 0.7 mm before tdc using a comparator
(3) at 14 mm along the flywheel rim
I have it set at 4.5 mm using a home made device to measure the piston from tdc because 4.5 is what the ignitions instruction said would it be better to go by what the cylinder says?
If you look at #3 do they mean to measure from tdc 14mm along the flywheel rim to the spark line ?

 

[Zelu]

I hv this rotor and Evo2 70cc. 4.5 mm It's ok ! I check 3mm, 2mm and this what sad manual - 4.5 mm - this is the best timing !
I hv only problem with light .. If U hv time maybey U can help me with this..
I don't hv light yet. I don't know before what are this cables.
This is my all free cables.

http://w3.bikepics.com/pics/2007\12\02\bikepics-1104051-full.jpg
http://w3.bikepics.com/pics/2007\12\02\bikepics-1104048-full.jpg

Red one is from CDI and second cable is from rotor.
Where I can fix them ? Which is from light ?
​

 

[manny]

the first picture red wire shouts the ignition off when you touch it to ground . My bike USA model the kill switch gives ground when in the on position so I put relay to reverse this (now when I hit kill switch it gives ground to the red wire you have)your bike might not be reversed like mine
the second picture is the plug that used to go on the old stator this plug comes from the old cdi you can take that off it is not needed anymore.

 

[Rage]

Ok so I installed the polini inner rotor ignition the instructions for the timing said to set it at 4.5mm from udc (upper dead center)for a 70cc
I tried to check the advance with a timing light but I have to get a tach .
I just found the instructions from the evo A/C cylinder I,'m using and it says
set the ignition advance:
(1) at 13 before tdc at 7000rpm
(2) at 0.7 mm before tdc using a comparator
(3) at 14 mm along the flywheel rim
I have it set at 4.5 mm using a home made device to measure the piston from tdc because 4.5 is what the ignitions instruction said would it be better to go by what the cylinder says?
If you look at #3 do they mean to measure from tdc 14mm along the flywheel rim to the spark line ?

From what you wrote.....

(1) at 13 before tdc at 7000rpm
(2) at 0.7 mm before tdc using a comparator
(3) at 14 mm along the flywheel rim

Then you wrote...
I have it set at 4.5 mm using a home made device to measure the piston from tdc.

Surely if you are measuring piston travel and refer to (2) the measurement needs to be 0.7mm not 4.5mm otherwise it will be too advanced, you will struggle to start it or it will backfire and stuff or just blow your engine up...:henko:

If you can't measure piston travel correctly and don't have a timing light (best method) then get your piston to TDC mark the flywheel if it doesn't have it marked on allready then measure 14mm advance (to the right) then set the tming to this. I'd use the timing light first though then piston travel and if your totally stuck flywheel measurements (not as accurate).

 

[Zelu]

But 0.7 isn't good timing ! Not with this ignition.
Polini in manual with cylinder Evo sad that your ignition need to set 0.7 before T.D.C but probably with oryginal ignition or older Polini Ignition (P171.0521 ? ) ..
With new Evo rotor in manual they wrote 4.5 mm before T.D.C ( with 70cc tuned cylinder ) and this is a good timing.
I seted my rotor with diffrent timing and this was the best .. +ralf+
​

 

[manny]

Rage I set the ignition to 4.5 before tdc because thats what the inner rotor ignition instructions said to do My question was should I follow the instructions from the cylinder or the instructions from the ignition ?

 

[Rage]

I'd go by the ignition instructions BUT when you start the engine listen out for pre- ignition especially when the engine is under load.
Some times the degrees BTC on a static setting can bear no relation the the actual firing point when the engine is running, that's why it's always better getting a strobe light on it when you have the engine running.

 

[manny]

hey rage I got A light from my brother today with tachometer built in for 2 and 4 stroke . I had the timing set perfect with a caliper at 4.5 before tdc and when I checked with the light it was way off I pulled the plug and you can see i had crazy detonation so to all forget measuring just get a light even if you have to beg, borrow or steal

 

[Zelu]

How many mm it was mistake ? About 0.5 mm ?
Maybey I would check my ignition with light ?
​

 

[Rage]

I use measurments to rough set and a timing light to get it spot on.

 

[manny]

I didnt remeasure the piston from TDC but I moved the plate that olds pickup on ignition about 10 MM of the top of my head if not more I cant believe the bike even ran I puled the plug and it showed detonation